Thioindigo vat dyestuffs and process of making same



Patented June 14,1927.

UNITED STATES PATENT OFFICE.

mm. amass, CARL Josnr mi ten, AND mmsr Bummer nocns'r-on rnn AND mam sonanrrnn, or mmxnnm-on-rnn-raunus, enmrm, xssrenoas T emssnnnr DYESTUFF coaroaa'rron, on NEW roan, it. an, a coarom'rron OF DELAWARE.

'rnromnmo var nxnsrnrrs Aim rnooass or .naxfna Sm.

No Drawing. Application flied June 22, 1926, Serial No. 117,850, and in Germany June 27, 1925.

Our present invention relates to a new process for producing hexa-substituted thioindigo vat dyes.

We have found that 6-6-dihalogen-4-4'- dimethylthioindigo can be halogenated so as to yield tetrahalogendimethyl thioindi 0 which gives on cotton very useful brig t reddish-violet tints of a normal tinctorial power which resemble the dyeings obtainable 1 by means of 5-5 dihal0gen-7 -7 -dimethylthioindigo. The dyeings are, in contrast to those produced by most of the thioindig'o dyestuffs, absolutely fast to boiling and therefore the new dyestuflf may be utilized for certain purposes which require the use of dyestuffs of an extremely 00d fastness to boiling, for instance for t e dyeing of articles to be bleached.

The halogen enters into the two 5-positions of the molecule and not the 7 -positions. The efiect of the halogenation is surprising. It was to be presumed that the halogen would enter into the 7 position which is not hindered by two ortho-situated substituents and that the tinctorial power of the dyestufl would be considerably weakened by the hexasubstitution.

To have moreover ,tound that the intro- 7 duction of halogen into the 5-position can not only be effected in the 6-6=dilialogen- 4-4'-dimethylthioindigo, but also in the 6-6 1 4-tetrahalogenthioindigo and also in the 6-6-44-tetramethylthioindigo and likewise in the 4-4-dihalogen-6-6-dimethylthioindigo. The dyestufis thus obtained which possess a normal tinctorial power, dye cotton violet to violet-red shades of excellent fastness to boiling.

The halogenation can be performed by 4 one of the known methods, while taking precautions as us ial in halogenatin processes.

. In our new rocess the use 0 chlorosulfonic acid as diluent has proved to be particularly suitable, also a mixture of chlorosulfonic acid with anhydrous'sulfuric acid. When using chlorosulfonic acid together with bromine, regard must be had to the 1 oxidation of the hydrobromic acid which is formed in this case.

60 5 For .the purpose of accelerating the halo of about 10 parts of bromine in 3 times the quantity of chlorosulfonic acid is run into the mixture which is then stirred for 2-3. hours. After the mass has been poured on ice and worked up, the 5-5'-dibromo-6-6- dichloro-4-4 dimethylthioindigo is obtained which dyes cotton bri ht reddish-violet tints.

2. 20 parts by weig t of 6-6 -dichloro-4-4'- dimethylthioindigo are suspended in 10-15 times the quantity of 'mtrobenzene and mixed with 18-20 parts of bromine. After having stirred the niixture for a short time at ordinary temperature, it is slowly heated to 130140. As soon as the evolution of hydrogen, bromide has ceased, the nitrobenzene is heated for a short time to boiling and the whole is allowed to cool.

The dyestufi', afterbeing vfreed from nitros benzene, dyes cotton from a yellow vat reddish-violet tints which very much resemble those obtainable according to Example 1.

3. 20 arts by weight of 6-6-dichloro-4-4'- dimethy thioindigo are introduced, while well coolin into 6-10 times the quantity of chlorosu fonic acid. There is added a very little quantity ofiodine and then are gradually introduced 15 parts of chlorine. The whole is then again stirred for a little while and then poured mice. The isolated dyestufi, which constitutes 5-5'-6-6 -tetrachlor-4-4-dimethylthioindigo, dyes cotton fast reddish-violet-tints. The dyeings roduced thereby are even somewhat brig ter than athose obtainable according to Examples 1 an '2. v Y

4, 20' parts by weight of fL-A diGhIorO-G-W- dimethylthioindigo are suspended in 15-20 times the uantity of 'nitrobenzene and on addition oi 18 parts of bromine the whole is gradually heated to 130. After the evo- 5 lution of hydrogen bromide has ceased, the

2. Process of producing hexa-substituted thioindigo vat dyestufl's, consistin in halo-' gienating 6-6-diha1ogen-4 -4e'-dimet ylthioinigo.

3. Process of producing hexa-substituted' thioindigo vat dyestufi's, consisting inhaloo genating 6-6-dichloro-4-4'-dimethylth1omdi o.

2. Process of producing hexa-substituted thioindigo vat dyestuffs, consisting in chloe mixture is heated to boiling for a short time, rinating a thioindigo compound of the folo whereupon it is cooled and filtered. The lowing constitution: new dyestuif thus produced constitutes 4-4'-- I dichloro-5-5'-dibromo-6-6-dimethy1thioindigo and dyes cotton very bright reddishviolet shades of excellent 'fastness. 70

5. 43,4 parts by weight of 4-4"-6-6-tetrachlorothioindigo are. dissolved, while Well cooling, in 6-10 times the quantity of chlorosulfonic acid; on addition of a very little quantity of antimony pentachloride there R n 1 represent halogen or a 75 are very slowly introduced about 35-40 parts methyl 'QuP- v ef chlorine. The mixture, after having @0955 of Producmg exe b stirred it for a little while, is poured on ice, l l 5 ,dyestufls coflslfitmg -9 1 filtered and washed until it is neutral. The s' s thy 4 L-5-5f-6-6'-hexachloro thioindigo forms a dlgo- I 80 claret-red powder which gives on cotton ex- 110C653 Q prpducmg .hQxafsubfitltm/ed tmmelv fast Violet tints thioindigo vat dyestuffs, cons sting in chlothioindigo, as used in Example 3, is subv Stituted the same parts by Weight of 5 7, As new products hexa-substltuted thio- 85 dichloro-6-6-dimethylthio1ndigo, a dyestufi ml Vat ye the followlllg constl' dyeing quite similar tints is obtained which tut-Ion: constitutes the hitherto unknown 4-4-'5-5'- tetrachloro-6-6'-dimethylthioindigo.

We do not claim as new products the dye- 9o stufl's of the formula:

CH: 0o 00 wherein R and R represent halogen or a 95 mg methyl group. v a s s 8. As a new (product, the herein described 40 thiolndigovat yestuifof the followingcon- I We claim: StltlltlODZ I I 1. Process of producing hexa-substituted c1 01 m0 thioindigo vat dyestuffs, consisting in halogenating a thioindigo compound of the fol- C1 ow ng constitution: i

i R R Q Y= o o- 5 i i I i i 9-. Materials dyed with the, new dyestuffs 5o 2 2' e RI 1 1' '7' of clalm 7. Y J I 10. Materials dyed with the new dyestufi' of claim e wherein R and R represent halogen or a In testlmony whereof, e mix g 56k group natures.

KARL THIESS. CARL JOSEF MULLER.

ERNST RUNN E. ALBERT SOHAEFFER, 

